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Physics-regularized Machine Learning To Approximate 3D Ideal-MHD Equilibria At Wendelstein 7-X
(2024)
The magnetohydrodynamic (MHD) equilibrium model is one of the fundamental building blocks in the description of a magnetically confined plasma. The computational cost of constructing solutions to the 3D ideal-MHD equilibrium problem is one of the limiting factors in stellarator research and design; in particular, it limits the extent to which we can perform sample-intensive applications, applications which require many samples to be evaluated to yield meaningful results. Sample-intensive applications in stellarator research and design include, for example, equilibrium reconstruction, stellarator optimization, and flight simulators. In this thesis, we investigate how faithfully artificial neural networks (NNs) can quickly approximate ideal-MHD equilibria in stellarator geometries, starting with Wendelstein 7-X (W7-X), the world’s most advanced stellarator. In particular, we investigate (see section 1.7):
RQI: to what extent can NN models approximate the MHD equilibrium solution for different W7-X configurations and plasma profiles? What
is the speed-accuracy trade-off offered by NN models?
RQII: to what degree the NN model faithfully reproduces equilibrium quantities of interest (e. g., MHD stability)? To what extent can NN models meet the requirements of downstream applications (e. g., Bayesian
inference, stellarator optimization) in terms of equilibrium quantities
accuracy?
RQIII: whether we can exploit the implicit representation of a MHD equilibrium, i. e., the equilibrium solution should satisfy the ideal-MHD force
balance equation, to improve the NN approximation’s accuracy;
RQIV: the reconstruction of the full posterior istribution of plasma parameters and equilibrium quantities with self-consistent MHD equilibria; moreover, how does the adoption of MHD equilibria approximated by NN models affect the inferred plasma parameters?
A deep NN model is developed to learn the ideal-MHD solution operator in W7-X operational subspace, yielding 3D equilibria up to six orders of magnitude faster than currently available MHD equilibrium codes. Physics domain knowledge is embeded into the NN model: equilibrium solution symmetries are satisfied by construction, and the MHD force balance regularizes the NN model to satisfy the ideal-MHD equations. The model accurately predicts the equilibrium solution and it faithfully reproduces global equilibrium quantities and proxy functions used in stellarator optimization. Finally, the developed fast NN equilibrium model has been applied in downstream applications to obtain W7-X configurations with improved fast-particle confinement and to infer plasma parameters with self-consistent MHD equilibria at W7-X.
Das Glioblastom ist ein hochmaligner und aggressiver Hirntumor, der von der WHO als Grad IV eingestuft wird. Die Betroffenen haben eine mittlere Überlebenszeit von 12 bis 15 Monaten, was auf dem invasiven Wachstum und der Chemo- und Radioresistenz des Tumors beruht. Dadurch existiert keine kurative Behandlung und es kommt in nahezu allen Fällen zu Rezidiven. Zunehmend wird deutlich, dass das Glioblastom einen stark veränderten Energiestoffwechsel aufweist, wobei das sogenannte lipidomic remodelling (Koundouros und Poulogiannis, 2020), welches für maßgebliche Alterationen im Fettsäuremetabolismus sorgt, besonders interessant erscheint. Die Fettsäureoxidation sowie damit assoziierte Prozesse und Proteine sind als eine bedeutende Energiequelle in den Fokus der Forschung getreten. So auch der hoch-affine Carnitintransporter OCTN2 (SLC22A5), welcher essentiell für den Carnitinhaushalt und damit die β-Oxidation der Zelle ist. In der vorgelegten Arbeit wurde daher das komplexe OCTN2/L-Carnitin System in seiner Funktion als potenzielle pharmakologische Zielstruktur zur therapeutischen Intervention beim Glioblastom tiefergehend untersucht und vorhandenes Wissen weiter ausgebaut. Hierzu diente eine Vielzahl experimenteller Bedingungen und Methoden, um Teilcharakteristiken des Glioblastoms darzustellen und die Bedeutung des OCTN2/L-Carnitin System zu überprüfen.
Da in vorausgegangenen Studien eine erhöhte Expression von OCTN2 mit einem signifikant schlechteren Überleben von Patienten mit Glioblastom nachgewiesen werden konnte, wurden als weitere potentiell interessante Zielstrukturen der niedrig-affine Carnitintransporter OCTN1 (SLC22A4) sowie Komponenten der β-Oxidation (CPT1C, CRAT) in die Patientenanalysen eingeschlossen. Zwar konnte für OCTN1 eine signifikant erhöhte mRNA-Expression in den humanen Glioblastomproben festgestellt werden, diese war jedoch nicht mit dem Überleben der Patienten assoziiert. Auch CPT1C und CRAT zeigten sich nicht als relevante Zielstrukturen beim Glioblastom.
In den durchgeführten Zellkulturexperimenten mit humanen LN-18 und murinen GL261 Glioblastomzellen zeigten sich partiell signifikante Effekte auf die wachstumsfördernden Kinasen AKT1 und ERK1/2, deren Phosphorylierungsgrad durch L-Carnitin moduliert wurde und die damit möglicherweise an carnitinvermittelten Wirkungen beteiligt sein könnten. Auf die Zellviabilität und Zellvitalität ließen sich hemmende Wirkungen des OCTN2-Inhibitors Meldonium sowie des CPT1-Hemmstoffes Etomoxir nachweisen, welche teilweise durch die zusätzliche Gabe von L-Carnitin revertiert wurden. Hinsichtlich der durch Zytostatika (Doxorubicin, Carmustin, Vincristin und Temozolomid) induzierten Apoptose konnte L-Carnitin nur die durch Carmustin in niedriger Dosierung ausgelöste Caspase-3 Aktivierung verhindern. Ein durch L-Carnitin ausgelöster Effekt auf die Migration der Glioblastomzellen konnte nicht nachgewiesen werden, jedoch wurde die migratorische Aktivität durch die Zytostatika Temozolomid und Carmustin, sowie interessanterweise auch durch den CPT1-Inhibitor Etomoxir, beeinträchtigt.
Um die Möglichkeit einer zielgerichteten Therapie gegen das OCTN2/L-Carnitin System präklinisch zu evaluieren, wurden tierexperimentelle Studien durchgeführt. Unter Verwendung eines orthotopen Glioblastommodelles der Maus konnte gezeigt werden, dass Etomoxir und Meldonium einen hemmenden Einfluss auf das in vivo Tumorwachstum besitzen, wobei dieser Effekt nur für den OCTN2-Inhibitor Meldonium signifikant ausfiel. In den OCTN2-defizienten jvs(-/-)-Mäusen konnte keine ausreichende Anzahl von Versuchstieren erreicht werden, um zuverlässige und finale Aussagen zu tätigen. In den heterozygoten jvs(+/-)-Mäusen, die zwar phänotypisch unauffällig sind, aber durch die geringere OCTN2 Ausstattung verminderte Carnitin-Gewebespiegel aufweisen, zeigte sich eine leichte, nicht signifikante Reduktion des intrazerebralen Tumorwachstums im Vergleich zu den C57BL/6-Wildtyp Mäusen.
Zusammenfassend wurde in der vorliegenden Arbeit das OCTN2/L-Carnitin System und seine Bedeutung für das Glioblastom umfassend dargelegt und experimentell überprüft. Als Endresultat dieser Studie können Etomoxir und Meldonium als Substanzen zur zielgerichteten Beeinflussung des Glioblastomwachstums angesehen werden und sollten in weiteren Versuchsreihen detailliert auf ihre Eignung für die Entwicklung neuer Therapieformen überprüft werden.
Zink-Transporter 8-Autoantikörper sind auch in Kindern ohne hereditäres Diabetes-Risiko in der Lage, das Erkrankungsrisiko zu stratifizieren, was auf eine ähnliche Pathophysiologie hinweist, und insbesondere in anderweitig als niedrig-risikobehaftet eingestuften und in IA-2A-negativen Individuen diejenigen identifiziert, die manifestieren werden.
ZnT8A sind zudem hilfreich in der Identifizierung eines autoimmun-vermittelten Diabetes mellitus im Erwachsenenalter, insbesondere bei phänotypisch als T2D eingestuften Patient*innen, sodass eine entsprechende Therapie und damit die Prognose sowie das Langzeit-Outcome in diesem Patientenkollektiv positiv beeinflusst werden kann.
Das entsprechend des SNP im kodierenden SLC30A8-Gen getriggerte Reaktionsmuster ist in T1D-Patient*innen und hoch-risikobehafteten Kindern mit überwiegend davon unabhängiger Autoantikörperantwort gegenüber der ZnT8WA-dominierenden Antwort in LADA-Patient*innen deutlich different, was die Hypothese unterschiedlicher Pathomechanismen dieser beiden Diabetesformen unterstützt.
Die zusätzliche Testung von ZnT8QA trägt nicht zu einer zusätzlichen Risikostratifizierung bei, sodass ein kombiniertes ZnT8A-Screening mit einem ZnT8-Arg325-Trp325-Hybridkonstrukt eine deutliche Zeit- und Kostenersparnis ohne Sensitivitätsverlust darstellt.
Bei spezifischen klinischen Konstellationen ist eine Lumbalpunktion zur Liquoranalytik
wichtig, um die Ätiologie der epileptischen Anfälle bzw. eines Status epilepticus zu klären und
alternative Erkrankungen auszuschließen. Die im Rahmen der vorliegenden Studie entwickelte
IDEAL-Checkliste stellt vor diesem Hintergrund einen einfach umzusetzenden und in den
klinischen Alltag leicht zu implementierenden Algorithmus dar, der behandelnde Ärztinnen
und Ärzte bei der Entscheidung für oder gegen die Durchführung einer Liquoruntersuchung
unterstützt. Gleichzeitig bewahrt die Anwendung der Checkliste Patientinnen und Patienten vor
einer nicht notwendigen Liquorpunktion mit entsprechenden Risiken. In den hier vorliegenden
Studien hätte bei etwa der Hälfte der Fälle (43 % in der prospektiven bzw. 49 % in der
retrospektiven Kohorte) auf eine Lumbalpunktion verzichtet werden können. Damit hätten die
periprozedurale Belastung der Patientinnen und Patienten sowie potentielle Komplikationen
einer Lumbalpunktion vermieden werden können.
Gleichzeitig besteht aufgrund des hohen negativen prädiktiven Wertes von 99-100 % eine hohe
Wahrscheinlichkeit eine liquorrelevante Ätiologie auch nicht zu übersehen, wenn kein Item der
kombinierten IDEAL-Checkliste zutrifft und damit auf eine Lumbalpunktion zur Liquoranalyse
verzichtet wird.
Eine multizentrische, prospektive Beobachtungsstudie sollte unter Anwendung der nationalen
und demographischen MoCA-Werte und auch im Hinblick auf unterschiedliche
Diagnostikstrategien bzw. Indikationskriterien, die breite klinische Anwendung, aber auch die
Erfassung seltener Ätiologien (z. B. immunsupprimierte Patientinnen und Patienten,
systemische Autoimmunerkrankungen) zur weiteren Validierung der IDEAL-Checkliste
erfolgen.
Modulation der Immunantwort durch Vagotomie im Mausmodell der postoperativen Immundysfunktion
(2024)
Die postoperative Immunsuppression ist ein häufiges Problem nach großen abdominalchirurgischen Eingriffen und geht mit einer erhöhten Mortalität insbesondere durch septische Komplikationen einher. Eine wichtige Rolle bei der Entstehung der Immunsuppression spielt der Nervus vagus, dies ist schon lange als cholinerger antiinflammatorischer Signalweg (engl. CAP) bekannt, wobei weder die Signalkaskaden auf zellulärer Ebene noch die Effekte des Nervus vagus hinreichend verstanden sind und kontrovers diskutiert werden.
Anhand der vorliegenden Ergebnisse dieser Arbeit lässt sich feststellen, dass das Traumamodell der surgically-induced immune dysfunction (SID) weitreichende Auswirkungen auf das Immunsystem hat. So konnten in-vivo signifikant veränderte Serumspiegel von IFN-γ, IL-2 und IL-6 gemessen und somit vorherige Ergebnisse anderer Arbeiten unserer Forschungsabteilung bestätigt werden. Außerdem führte die SID zu deutlichen Veränderungen hinsichtlich der Abwehrlage des angeborenen Immunsystems: wir fanden erniedrigte CD4+/CD8+-Relationen innerhalb der T-Zell-Population sowie insbesondere in der Spätphase ein erhöhtes Ly6Chigh/Ly6Clow-Verhältnis als Ausdruck einer gestörten angeborenen Immunabwehr durch patrolling macrophages, welche sich zusätzlich durch eine Abnahme der MHCII-Expression auf den Makrophagen unter Vagotomie äußerte.
Bei der ex-vivo-Betrachtung des Immunsystems unter Hinzunahme von Funktionstests mit Lipopolysaccharid (LPS) konnten wir beobachten, dass der Ablauf der Immunreaktion anhand der TNF-α-Ausschüttung von Makrophagen interessante Ähnlichkeiten mit dem bekannten SIRS-CARS-Modell der Sepsis aufweist. Wir konnten zeigen, dass die Vagotomie insbesondere in der Frühphase nach SID die hyperinflammatorische Reaktion der Milzmakrophagen noch weiter verstärkt. In der Spätphase 72 Stunden nach Trauma hat die Vagotomie einen geringeren Einfluss auf die Immunantwort und führt zu einer verstärkten Suppression, die allerdings nicht so stark ausgeprägt ist wie die Hyperinflammation in der Frühphase. Die Ausschaltung des N. vagus führt also in beiden Phasen zu einer Abweichung zu den Extremen hin und bedingt eine nachhaltige Störung des immunologischen Gleichgewichts.
Mit der vorliegenden Arbeit konnte ein wichtiger Beitrag zur Grundlagenforschung dieses klinisch so bedeutsamen Problems geleistet werden. Weitere Untersuchungen auf diesem Gebiet sind notwendig, um in Zukunft nach operativem Trauma z.B. in Form von spezifischen Agonisten am alpha7-Rezeptor eine wirksame Therapie oder besser eine Prophylaxe zur Vermeidung anbieten zu können.
Copper tungsten oxide films are deposited with the help of reactive high power impulse magnetron sputtering (HiPIMS) in an argon/oxygen gas mixture. Two magnetrons, one equipped with a tungsten target and the other with a copper target, are employed. The HiPIMS discharge is operated with a repetition frequency of f=100 Hz. Pulse widths of 100 and 20 µs separated by 25 µs are chosen for the tungsten and copper target, respectively. Films deposited on two different glass substrates [soda lime glass and fluorine doped tin oxide (FTO) coated glass] are characterized by energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, Raman spectroscopy, and ellipsometry. Photoelectrochemical activity was investigated by linear voltammetry. The composition and crystal structure of as-deposited and annealed films are found to depend on the deposition conditions. Annealed films deposited on FTO glass are composed of WO3 and CuWO4 or Cu2WO4 crystal phases. Films deposited on soda lime glass are subject to sodium diffusion into the films during annealing and the formation of Na2W2O7 and Na2W4O13 phases.
This article sheds light on the obstacles that women face as members of the government by answering the questions: How does the sex of ministers shape the way MPs’ assess the quality of their work? And, how does this relationship differ depending on the political ideology of MPs? We argue that legislators assess the competencies of women ministers differently after the activation of gender stereotypes, but that the way they react depends on the ideological orientation of their party. We investigate this topic in a real-word context using a unique survey experiment with German and Austrian MPs. The evidence reveals that, while MPs belonging to right-wing parties perceive women in the executive as less competent than men ministers, their colleagues from left-wing parties actually assess them more favorably. These findings highlight the persistence of old myths about women’s lacking political skills and the emergence of new ones about women’s superior ability to govern.
Introduction: Adiposity and excessive weight are on the rise in western industrialized countries. In cases where conservative measures fail and surgical interventions are not (yet) desired, gastric balloon therapy has proven to be a safe and reversible endoscopic method. Methods: Aside from weight progression under gastric balloon therapy and by using MRI, our research paper describes the behavior of different abdominal body fat compartments at the beginning and at the end of the gastric balloon therapy. Additionally, the volume of the left liver lobe as well as the fill volume and performance of the gastric balloon were analyzed over the duration of treatment. For assessing potential impacts of weight reduction on the muscle mass, we determined the area of the m. psoas on a comparable cross-sectional area at the beginning and at the end of the therapy. Results: We were able to verify a significant reduction of the layer of subcutaneous fat, adipose capsule of the kidney, and intra-abdominal fatty tissue during the therapy. The volume of the left liver lobe was shrinking in addition to a muscle loss during the balloon therapy. The volume of the gastric balloon remained stable (not hyperinflation). There were variable gas bubbles in the gastric balloon. Conclusion: The gastric balloon is a temporary and successful option for weight reduction by reducing body fat, liver volume, but also muscle mass.
Thioredoxine (Trxs) bilden eine Familie ubiquitärer Oxidoreduktasen, welche durch posttranslationale Redox-Modifikationen von Cysteinyl-Thiolgruppen sowie die Regulation der intrazellulären Wasserstoffperoxidgehaltes die zelluläre Redoxantwort steuern. Es ist bekannt, dass Thioredoxine, Glutaredoxine (Grxs) und Peroxiredoxine (Prxs) wesentliche Signalwege von Inflammation, Proliferation und Apoptose beeinflussen und somit in vielen Pathologien, insbesondere bei entzündlichen Erkrankungen wie dem allergischen Asthma, eine entscheidende Rolle spielen. Derzeit sind vorwiegend die intrazellulären Funktionen der Proteine der Trx-Familie in Gesundheit und Krankheit umfassend untersucht, doch die extrazellulären Funktionen bei der Redox-Signalübertragung bleiben bis zum heutigen Tage weitestgehend im Dunkeln. In dieser Arbeit haben wir uns daher zum Ziel gesetzt, Verteilung und Funktion von Proteinen der Trx-Familie in der Regulation der Immunantwort zu untersuchen, wobei der Schwerpunkt auf dem extrazellulären Vorkommen und den damit verbundenen Eigenschaften liegt.
Allergische Atemwegsentzündungen sind durch bronchiale Obstruktion und chronischen Umbau sowie Hyperreagibilität der Atemwege gekennzeichnet. Die Anhäufung reaktiver Sauerstoffspezies in der bronchialen Flüssigkeit der Lunge und die sich daraus ergebenden Veränderungen des Redoxzustands in den bronchialen Epithelzellen sind in den letzten Jahren in den Fokus der Asthmaforschung gerückt. Mehrere Studien beschrieben eine positive Wirkung von Trx1 und Grx1 in Atemwegsinfektionen, so würde eine Th2-typische Immunmodulation reduziert und verringere in der Folge den Umbau der Atemwegsstruktur – eine zentrale Pathologie des Asthmas.
In dieser Studie untersuchten wir die Expressionsniveaus von Proteinen der Trx-Familie in Lungengewebe und bronchoalveolärer Lavageflüssigkeit in einem Mausmodell der Ovalbumin (OVA) induzierten allergischen Atemwegsentzündung. Wir konnten eine Zunahme von Grx2 und Prx4 in intrazellulären Proben aus der Mäuselunge nach einsetzen der induzierten Atemwegsinfektion zeigen. Ausschließlich unter OVA-induzierter Inflammation wurde in diesen Proben eine zweite Isoform von Grx2, zytosolisches Grx2c, nachgewiesen. Die Behandlung von Mäusen mit intraperitoneal appliziertem, rekombinantem Grx2 parallel zur Induktion der Entzündung mit OVA, hatte eine entzündungshemmende Wirkung, die zu einer Verringerung des asthmatischen Phänotyps in der Immunhistochemie und einer signifikanten Reduktion der Gesamtzahl der Entzündungszellen, besonders der eosinophilen Granulozyten führte. Die Verabreichung der rekombinanten Grx2C40S-Mutante, der die Fähigkeit zur Katalyse des Dithiol-Reaktionsmechanismus fehlt, hatte nicht die gleiche entzündungshemmende Wirkung. Eine zusätzlich durchgeführte His-Tag-Färbung zeigte eine Aufnahme von rekombinantem Grx2 in die Epithelzellen und Makrophagen der entzündeten Lunge. Die Färbung von Lungenabschnitten für HIF1- und Pro-Caspase3 nahm nach Beginn der allergischen Atemwegsentzündung zu und ging bei den mit dem wildtyp Grx2 behandelten Mäusen deutlich zurück.
In den extrazellulären Fraktionen war die Konzentration von Trx1, Grx1, Prx2 und Prx4 unter Entzündungsbedingungen erhöht, zudem konnte Prx4 in dieser Studie erstmals nur in der Entzündung, nicht aber bei gesunden Mäusen nachgewiesen werden. In-vitro-Experimente, bei denen Makrophagen aus Balb/c-Mäusen stimuliert wurden, sollten Aufschluss über die Funktionen von Trxs und Grxs in der Immunantwort geben. Grx2 und Trx1 wurden als potenzielle Stimulatoren von Makrophagen identifiziert, die die Sekretion von RANTES, IL-6, IL-10 und TNF-α induzieren, während die Zytokinspiegel von IL-4 und INF-γ nicht verändert wurden. Bei kombinierter Verabreichung von Redoxinen mit LPS/IFN-γ, die einen Entzündungszustand nachahmt, wurde gezeigt, dass Trx1 die Zytokinspiegel von TNF-α und INF-γ im Vergleich zu LPS/IFN-γ allein senkt. Die Behandlung mit Trx1/LPS/IFN-γ induzierte die Produktion von IL-6 und RANTES auf ein Niveau vergleichbar mit der alleinigen Stimulation durch LPS/IFN-γ.
Diese Arbeit beleuchtet Proteinveränderungen von Thioredoxinen, Glutaredoxinen und Peroxiredoxinen in einem Mausmodell für allergische Atemwegsentzündungen mit besonderem Schwerpunkt auf der extrazellulären Verteilung und Funktion der Proteine. Wir zeigen, dass die Veränderungen der Proteinspiegel selektiv reguliert werden und zu einem fein abgestimmten Netzwerk von Partnern in der Redox-Signalgebung beitragen und somit Potenzial für mögliche Therapieansätze bieten.
Purpose
The German Retina.net ROP registry and its Europe-wide successor, the EU-ROP registry, collect data from patients treated for ROP. This analysis compares input parameters of these two registries to establish a procedure for joint analyses of different registry data using exemplary datasets from the two registries.
Methods
Exemplary datasets from the two databases over a 1-year period each (German Retina.net ROP Registry, 2011, 22 infants; EU-ROP Registry, 2021, 44 infants) were compared. The parameters documented in the two databases were aligned and analysed regarding demographic parameters, treatment modalities, complications within first 24 h and retreatments.
Results
The current analysis showed that data can be aligned for joint analyses with some adjustments within the data structure. The registry with more detailed data collection (EU-ROP) needs to be reduced regarding granularity in order to align the different registries, as the registry with lower granularity determines the level of analyses that can be performed in a comparative approach. In the exemplary datasets, we observed that the overall most common ROP severity in both registries was zone II, 3+ (2011: 70.5%; 2021: 65%), with decreasing numbers of clock hours showing preretinal neovascularisations (2011: 10–12 clock hours in 29% of cases, 2021: 4–6 clock hours in 38%). The most prevalent treatment method was laser coagulation in 2011 (75%) and anti-VEGF therapy in 2021 (86.1%). Within the anti-VEGF group, all patients were treated with bevacizumab in 2011 and with ranibizumab in 2021. Retreatment rates were comparable in 2011 and 2021.
Conclusion
Data from two different ROP registries can be aligned and jointly analysed. The analysis reveals a paradigm shift in treatment modalities, from predominantly laser to anti-VEGF, and within the anti-VEGF group from bevacizumab to ranibizumab in Germany. In addition, there was a trend towards earlier treatment in 2021.
Hibernation is a widespread adaptation in animals to seasonally changing environmental conditions. In the face of global anthropogenic change, information about plastic adjustments to environmental conditions and associated mortality costs are urgently needed to assess population persistence of hibernating species. Here, we used a five-year data set of 1047 RFID-tagged individuals from two bat species, Myotis nattereri and Myotis daubentonii that were automatically recorded each time they entered or left a hibernaculum. Because the two species differ in foraging strategy and activity pattern during winter, we expected species–specific responses in the timing of hibernation relative to environmental conditions, as well as different mortality costs of early departure from the hibernaculum in spring. Applying mixed-effects modelling, we disentangled population-level and individual-level plasticity in the timing of departure. To estimate mortality costs of early departure, we used both a capture mark recapture analysis and a novel approach that takes into account individual exposure times to mortality outside the hibernaculum. We found that the timing of departure varied between species as well as among and within individuals, and was plastically adjusted to large-scale weather conditions as measured by the NAO (North Atlantic Oscillation) index. Individuals of M. nattereri, which can exploit milder temperatures for foraging during winter, tuned departure more closely to the NAO index than individuals of M. daubentonii, which do not hunt during winter. Both analytical approaches used to estimate mortality costs showed that early departing individuals were less likely to survive until the subsequent hibernation period than individuals that departed later. Overall, our study demonstrates that individuals of long-lived hibernating bat species have the potential to plastically adjust to changing climatic conditions, although the potential for adjustment differs between species.
We apply the charge simulation method (CSM) in order to compute the logarithmic capacity of compact sets consisting of (infinitely) many “small” components. This application allows to use just a single charge point for each component. The resulting method therefore is significantly more efficient than methods based on discretizations of the boundaries (for example, our own method presented in Liesen et al. (Comput. Methods Funct. Theory 17, 689–713, 2017)), while maintaining a very high level of accuracy. We study properties of the linear algebraic systems that arise in the CSM, and show how these systems can be solved efficiently using preconditioned iterative methods, where the matrix-vector products are computed using the fast multipole method. We illustrate the use of the method on generalized Cantor sets and the Cantor dust.
Hintergrund
Migräne ist eine hochprävalente Erkrankung, die bei betroffenen Patient*innen eine hohe Belastung sowohl durch die Kopfschmerzen an sich als auch durch die Einschränkung ihres Sozial- und Berufslebens hervorruft. Die Therapie besteht aus einer Akuttherapie der Kopfschmerzattacken sowie einer prophylaktischen Therapie zur Reduktion der Kopfschmerzfrequenz und -schwere. In der Prophylaxe stehen mit Antikörpern gegen das Calcitonin-gene-related-peptide (CGRP) und dessen Rezeptor erstmalig für die Migräne entwickelte gezielte prophylaktische Therapien zur Verfügung. Es stellt sich jedoch hierbei die Frage, ob CGRP-Antikörper lediglich symptomatisch in der Peripherie des trigemino-vaskulären-Systems wirken oder auch im zentralen Nervensystem die zugrundeliegenden pathophysiologischen Mechanismen beeinflussen, was einer krankheitsmodifizierenden Wirkung entspräche. Ziel unserer Studie war es, die Nullhypothese einer rein symptomatischen Wirkung gegen die Alternativhypothese einer Krankheitsmodifikation und somit zentralnervösen Wirkung, zu prüfen, indem bei Patient*innen mit episodischer Migräne der nozizeptive Blinkreflex vor und nach der Behandlung mit CGRP-Antikörpern untersucht wurde.
Methoden
22 Patient*innen mit episodischer Migräne (21 Frauen, 46,2 ± 13,8 Jahre alt) und 22 alters- und geschlechts-gematchte Kontrollen wurden im Rahmen dieser prospektiven Beobachtungsstudie eingeschlossen. Sie erhielten einen umfassenden Fragebogen zur Erhebung demografischer Charakteristika sowie der Kopfschmerzanamnese. Es erfolgte eine Messung des Blinkreflexes (10 Durchgänge à 6 Stimuli) vor (V0) und 3 Monate (V3) nach der Behandlung mit CGRP-Antikörpern (Kontrollen wurden einmalig gemessen). Im Rahmen der Messung wurden wiederholt schmerzhafte Stimuli supraorbital appliziert, die direkte Rückschlüsse auf die zentralnervöse Erregbarkeit des Hirnstamms als pathophysiologisch zentralen Mechanismus im Rahmen der Migräneentstehung zulassen. Die Area-under-the-curve (AUC) der R2-Komponente der Muskelsummenaktionspotentiale des Blinkreflexes sowie das Habituationsverhalten (Regressionskoeffizient über mehrere Blöcke) der stimulierten sowie nicht-stimulierten Seite wurden über 10 Blöcke hinweg evaluiert (primärer Endpunkt). Es wurde jeweils zuerst ein Test auf globale Veränderungen durchgeführt, der dann durch post-hoc-Analysen weiter spezifiziert wurde.
Ergebnisse
Alle Patient*innen zeigten eine signifikante Reduktion der Kopfschmerztage/Monat (V0: 12,4±3,3, V3: 6,6 ± 4,9) nach Beginn der Behandlung mit einem CGRP-/Rezeptorantikörper. Auf der stimulierten Seite reduzierte sich die AUC signifikant in den Blöcken eins, zwei sowie acht (Fglobal=5,86, p<0,001; block 1: R2a_s: -28%, p<0,001). Auf der nicht-stimulierten Seite zeigten sich Block eins, zwei, drei, acht sowie zehn als signifikant reduziert (Fglobal=8,22, p<0,001, block 1: R2a_ns: -22%, p=0,003). Die Veränderung der Habituation erwies sich in den Blöcken sechs, sieben, acht und zehn auf der nicht-stimulierten Seite als signifikant (Fglobal=3,07, p<0,001; block 6: R2h_ns: r=-1,36, p=0,007). Weder die AUC noch die Habituation des ersten Messtermins (V0) korrelierte mit dem späteren klinischen Ansprechen, sodass kein Prädiktor für das Therapieansprechen detektiert werden konnte (binär logistische Regression; alle Prädiktoren p>0,05).
Diskussion & Zusammenfassung
Die Ergebnisse dieser Studie zeigen, dass die dreimonatige Therapie mit CGRP-Antikörpern die Erregbarkeit des Hirnstamms als Antwort auf wiederholte schmerzhafte Stimuli bei Patient*innen mit Migräne normalisiert und liefert somit Hinweise für ein krankheitsmodifizierendes Potenzial. Veränderungen der Habituation korrelierten signifikant mit der Verringerung der Kopfschmerz-Frequenz, weitere Studien sind jedoch nötig, um zu eruieren, ob Parameter als Prädiktor geeignet sind um eine Voraussage über das Therapieansprechen und das Risiko einer Verschlechterung nach Beendigung der Therapie zu ermöglichen.
Representative epidemiologic data on the average volume of the parotid gland in a large population-based MRI survey is non-existent. Within the Study of Health in Pomerania (SHIP), we examined the parotid gland in 1725 non-contrast MRI-scans in T1 weighted sequence of axial layers. Thus, a reliable standard operating procedure (Intraclass Correlation Coefficient > 0.8) could be established. In this study, we found an average, single sided parotid gland volume of 27.82 cm3 (95% confidence interval (CI) 27.15 to 28.50) in male and 21.60 cm3 (95% CI 21.16 to 22.05) in female subjects. We observed positive associations for age, body mass index (BMI), as well as male sex with parotid gland size in a multivariate model. The prevalence of incidental tumors within the parotid gland regardless of dignity was 3.94% in the Northeast German population, slightly higher than assumed. Further epidemiologic investigations regarding primary salivary gland diseases are necessary.
Kognitive Beeinträchtigungen treten bei 43-70 % der Patient*innen mit Multipler Sklerose (MS) auf [1]. Der Symbol Digit Modalities Test (SDMT) ist ein kognitiver Test, der ein empfindliches Maß für die Informationsverarbeitungsgeschwindigkeit ist, und bei MS-Patient*innen häufig beeinträchtigt ist [2, 3]. In bildgebenden Studien wurden bereits die Bedeutung von Läsionen in der weißen Substanz, aber auch der grauen Substanz im Bereich des beidseitigen superioren Parietallappens (Brodman Areal [BA] 7A) für die Durchführung des SDMT hervorgehoben [4–6]. Bislang liegen jedoch nur wenige Daten speziell zur Integrität der von BA 7A absteigenden Bahnen der weißen Substanz vor. Ein Zusammenhang zwischen der Integrität des BA 7A Traktes der weißen Substanz und der Informationsverarbeitungsgeschwindigkeit bei Patient*innen mit Multipler Sklerose ist bisher noch unbekannt.
In dieser Studie untersuchten wir die Assoziation zwischen der Integrität des von BA 7A ausgehenden Traktes der weißen Substanz und der Leistung im SDMT in einer Gruppe von 101 MS-Erkrankten. Dazu verwendeten wir die Diffusionstensor Bildgebung (DTI), um diesen Trakt mit der probabilistischen Traktographie zu rekonstruieren. Anhand der quantifizierten mittleren fraktionalen Anisotropie (FA), ein Maß für die Abweichung von isotroper Diffusivität in allen Richtungen und der SDMT Leistung konnten wir mit und ohne Maskierung der zuvor festgestellten Läsionen der weißen Substanz mögliche Korrelationen berechnen. Dabei zeigte sich, dass die Werte der fraktionalen Anisotropie positiv mit den verminderten Ergebnissen des SDMT assoziiert waren. Für den kortikospinalen Trakt als Kontrolltrakt ergab sich diese Assoziation erwartungsgemäß nicht, da er mit motorischen und nicht mit kognitiven Beeinträchtigungen in Verbindung gebracht wird [7]. Der positive Zusammenhang blieb auch nach Maskierung der Läsionen innerhalb des BA 7A Traktes bestehen, was auf eine zusätzliche Schädigung der normal erscheinenden weißen Substanz schließen lässt.
Die Beziehung zwischen der Geschwindigkeit der Informationsverarbeitung bei Patient*innen mit Multipler Sklerose und der Integrität des BA 7A-Traktes der weißen Substanz wurde festgestellt. Durch diese Studie können weitere Erkenntnisse über die strukturelle Korrelation der weißen Substanz des Gehirns mit der kognitiven Leistung von MS-Erkrankten gewonnen werden. In der Zukunft ist eine Kombination aus strukturellen mit funktionellen Messungen sinnvoll.
Hematophagous leeches express a broad variety of secretory factors in their salivary glands; among them are hirudins, inhibitors of blood coagulation, and decorsins/ornatins, inhibitors of platelet aggregation. Here, we describe the identification and molecular and functional characterization of putative hirudins and decorsins/ornatins in two leech species of American origin, Limnobdella mexicana and Haementeria vizottoi. The leech species represent two orders of leeches, the proboscis-bearing Rhynchobdellida and the non-proboscis-bearing Arhynchobdellida. Members of the hirudin superfamily, such as hirudins or decorsins/ornatins, are described for the first time in the genus Haementeria. Both species expressed very potent inhibitors of platelet aggregation, but only the putative hirudins of L. mexicana displayed high thrombin-inhibitory potency, whereas the putative hirudin of H. vizottoi turned out to be a hirudin-like factor. The results of our study provide new insights into the evolutionary background of the blood-sucking lifestyle in leeches.
Although the common pathology of Alzheimer’s disease (AD) and white matter hyperintensities (WMH) is disputed, the gene TREML2 has been implicated in both conditions: its whole-blood gene expression was associated with WMH volume and its missense variant rs3747742 with AD risk. We re-examined those associations within one comprehensive dataset of the general population, additionally searched for cross-relations and illuminated the role of the apolipoprotein E (APOE) ε4 status in the associations. For our linear regression and linear mixed effect models, we used 1949 participants from the Study of Health in Pomerania (Germany). AD was assessed using a continuous pre-symptomatic MRI-based score evaluating a participant’s AD-related brain atrophy. In our study, increased whole-blood TREML2 gene expression was significantly associated with reduced WMH volume but not with the AD score. Conversely, rs3747742-C was significantly associated with a reduced AD score but not with WMH volume. The APOE status did not influence the associations. In sum, TREML2 robustly associated with WMH volume and AD-related brain atrophy on different molecular levels. Our results thus underpin TREML2’s role in neurodegeneration, might point to its involvement in AD and WMH via different biological mechanisms, and highlight TREML2 as a worthwhile target for disentangling the two pathologies.
The predominantly vegetative propagating duckweeds are of growing commercial interest. Since clonal accessions within a respective species can vary considerably with respect to their physiological as well as biochemical traits, it is critical to be able to track the clones of species of interest after their characterization. Here, we compared the efficacy of five different genotyping methods for Spirodela polyrhiza, a species with very low intraspecific sequence variations, including polymorphic NB-ARC-related loci, tubulin-gene-based polymorphism (TBP), simple sequence repeat variations (SSR), multiplexed ISSR genotyping by sequencing (MIG-seq), and low-coverage, reduced-representation genome sequencing (GBS). Four of the five approaches could distinguish 20 to 22 genotypes out of the 23 investigated clones, while TBP resolved just seven genotypes. The choice for a particular method for intraspecific genotyping can depend on the research question and the project budget, while the combination of orthogonal methods may increase the confidence and resolution for the results obtained.
Target Mechanisms of the Cyanotoxin Cylindrospermopsin in Immortalized Human Airway Epithelial Cells
(2022)
Cylindrospermopsin (CYN) is a cyanobacterial toxin that occurs in aquatic environments worldwide. It is known for its delayed effects in animals and humans such as inhibition of protein synthesis or genotoxicity. The molecular targets and the cell physiological mechanisms of CYN, however, are not well studied. As inhalation of CYN-containing aerosols has been identified as a relevant route of CYN uptake, we analyzed the effects of CYN on protein expression in cultures of immortalized human bronchial epithelial cells (16HBE14o−) using a proteomic approach. Proteins whose expression levels were affected by CYN belonged to several functional clusters, mainly regulation of protein stability, cellular adhesion and integration in the extracellular matrix, cell proliferation, cell cycle regulation, and completion of cytokinesis. With a few exceptions of upregulated proteins (e.g., ITI inhibitor of serine endopeptidases and mRNA stabilizer PABPC1), CYN mediated the downregulation of many proteins. Among these, centrosomal protein 55 (CEP55) and osteonectin (SPARC) were significantly reduced in their abundance. Results of the detailed semi-quantitative Western blot analyses of SPARC, claudin-6, and CEP55 supported the findings from the proteomic study that epithelial cell adhesion, attenuation of cell proliferation, delayed completion of mitosis, as well as induction of genomic instability are major effects of CYN in eukaryotic cells.
Background: Little is known about how substance use affects health-related quality of life (HRQOL) in depressed individuals. Here, associations between alcohol consumption and HRQOL in hospital and ambulatory care patients with past-year depressive symptoms are analyzed. Method: The sample consisted of 590 participants (26.8% non-drinkers) recruited via consecutive screenings. Individuals with alcohol use disorders were excluded. HRQOL was assessed with the Veterans Rand 12-item health survey (VR-12). Multivariable fractional polynomials (MFP) regression analyses were conducted (1) to test for non-linear associations between average daily consumption and HRQOL and (2) to analyze associations between alcohol consumption and the physical and mental health component summaries of the VR-12 and their subdomains. Results: Alcohol consumption was positively associated with the physical health component summary of the VR-12 (p = 0.001) and its subdomains general health (p = 0.006), physical functioning (p < 0.001), and bodily pain (p = 0.017), but not with the mental health component summary (p = 0.941) or any of its subdomains. Average daily alcohol consumption was not associated with HRQOL. Conclusion: Alcohol consumption was associated with better physical HRQOL. Findings do not justify ascribing alcohol positive effects on HRQOL. Data indicate that non-drinkers may suffer from serious health disorders. The results of this study can inform the development of future alcohol- and depression-related interventions.
Simple Summary
The treatment of high-risk neuroblastoma patients with anti-GD2 antibodies has improved survival, and it is an established treatment strategy; however, many patients still experience a late relapse. One disadvantage of passive immunotherapy is the absence of a memory response. Therefore, developing an active immunotherapy leading to a sustained immune response may provide a solution and prevent the occurrence of late relapses following anti-GD2 antibody therapy. Here, we describe the first-in-man compassionate use of the ganglidiomab vaccine following passive immunotherapy with an anti-GD2 antibody (dinutuximab beta) in seven neuroblastoma patients. The vaccine was well-tolerated, and all patients not pre-treated by haploidentical transplantation developed vaccine-specific immune responses.
Abstract
(1) Background: High-risk neuroblastoma (HR-NB) is associated with a poor prognosis despite a multimodal high-intensity treatment regimen, including immunotherapy with anti-GD2 monoclonal antibodies (mAb). Here, we investigated the effects of an anti-idiotypic vaccine based on the mAb ganglidiomab that structurally mimics GD2. (2) Methods: Patients with HR-NB treated with anti-GD2 mAb dinutuximab beta and who achieved complete remission after frontline or salvage therapy were offered the vaccine (0.5 mg ganglidiomab adsorbed to Alhydrogel®). Side effects (CTCAE v4.03) and immune responses were determined on each visit. We also evaluated the time to relapse or progression until the last follow-up. (3) Results: Seven HR-NB patients (five frontlines, two relapsed) received 6–22 subcutaneous injections every two weeks. Six of the seven patients showed an immune response. The non-responding patient had a haploidentical stem cell transplantation as part of the previous treatment. No fever, pain, neuropathy, or toxicities ≥ grade 3 occurred during or post-treatment. All immunized patients did not experience relapses or progressions of their neuroblastoma. (4) Conclusions: This is the first-in-man use of the ganglidiomab vaccine, which was well-tolerated, and all patients not pre-treated by haploidentical transplantation developed vaccine-specific immune responses. These findings provide an important basis for the design of prospective clinical trials.
Eicosanoids are lipid mediators generated from arachidonic acid with pro- and anti-inflammatory properties. Despite these lipid mediators being known for decades, quantitative determination in biological samples is still challenging due to low abundance, instability, the existence of regio- and stereoisomers, and a wide polarity range that hampers chromatographic separation. In this study, we developed a supercritical fluid chromatography mass spectrometry (SFC-MS) platform for the quantification of relevant eicosanoids. Application of a chiral amylose-based column and modifier combination of 2-propanol/acetonitrile offered separation and sufficient resolution of 11 eicosanoids (5-, 12-, 15-HETE, PGB1, LTB4, t-LTB4, 20-OH-LTB4, PGE2, PGD2, PGF2α, TxB2) with baseline separation of isobaric analytes within 12 min. The method was validated in terms of range (78–2500 ng/mL), linearity, accuracy, precision, and recovery according to EMA guidelines. Finally, we confirmed the method’s applicability by quantifying eicosanoid levels in human primary blood cells. In conclusion, we present a validated SFC-MS method for the determination of relevant eicosanoids in biological samples with a wide range of polarity while maintaining baseline separation of isobars, which allows coupling to a single quadrupole mass detector.
A New Laboratory Workflow Integrating the Free Light Chains Kappa Quotient into Routine CSF Analysis
(2022)
We performed this cohort study to test whether further analysis of intrathecal inflammation can be omitted if the free light chain kappa (FLCκ) quotient is within the reference range in the corresponding quotient diagram. FLCκ concentrations were measured in serum and cerebrospinal fluid (CSF) samples. The intrathecal fraction (IF) of FLCκ was calculated in relation to the hyperbolic reference range. 679 patient samples were used as a discovery cohort (DC). The sensitivity and negative predictive value (NPV) of the FLCκ-IF for the detection of an intrathecal humoral immune response (CSF-specific OCB and/or IF IgG/A/M > 0%) was determined. Based on these data, a diagnostic algorithm was developed and prospectively validated in an independent validation cohort (VC, n = 278). The sensitivity of the FLCκ-IF was 98% in the DC and 97% in the VC with a corresponding NPV of 99%. The use of the FLCκ-IF as a first line analysis would have reduced the Ig and OCB analysis by 62% in the DC and 74% in the VC. The absence of a FLCκ-IF predicts the absence of a humoral intrathecal immune response with a very high NPV of 99%. Thus, integration of our proposed algorithm into routine CSF laboratory analysis could help to reduce analytical efforts.
Amine transaminases (ATAs) are powerful biocatalysts for the stereoselective synthesis of chiral amines. However, wild-type ATAs usually show pH optima at slightly alkaline values and exhibit low catalytic activity under physiological conditions. For efficient asymmetric synthesis ATAs are commonly used in combination with lactate dehydrogenase (LDH, optimal pH: 7.5) and glucose dehydrogenase (GDH, optimal pH: 7.75) to shift the equilibrium towards the synthesis of the target chiral amine and hence their pH optima should fit to each other. Based on a protein structure alignment, variants of (R)-selective transaminases were rationally designed, produced in E. coli, purified and subjected to biochemical characterization. This resulted in the discovery of the variant E49Q of the ATA from Aspergillus fumigatus, for which the pH optimum was successfully shifted from pH 8.5 to 7.5 and this variant furthermore had a two times higher specific activity than the wild-type protein at pH 7.5. A possible mechanism for this shift of the optimal pH is proposed. Asymmetric synthesis of (R)-1-phenylethylamine from acetophenone in combination with LDH and GDH confirmed that the variant E49Q shows superior performance at pH 7.5 compared to the wild-type enzyme.
Background: Colorectal carcinoma (CRC) is a heterogeneous disease, and differences in outcomes have been reported among patients diagnosed with the same disease stage. Prognostic and predictive biomarkers provide information for patient risk stratification and guide treatment selection. Although numerous studies have analyzed the effects of systemic inflammatory factors on CRC outcomes, clinical significance remains to be elucidated. In particular, the treatment strategy of colon cancer patients is different from that of rectal cancer due to outcome and recurrence differences. The identification of patients with a poor prognosis who might benefit from intensive treatment approaches is clinically necessary. Methods: This study aimed to evaluate the value of different blood-based markers and assess the significance of our newly developed inflammatory-nutrition-related biomarker (NCR = BMI × albumin/CRP) in patients with colon cancer. A two-stage design was used with 212 patients with colon cancer (CC) in the discovery cohort (n = 159) and in an external validation cohort (n = 53). Results: A lower preoperative NCR level was significantly correlated with a worse prognosis, sidedness, undifferentiated histology, nodal involvement, and advanced UICC stage. We compared the NCR with other established prognostic indices and showed that the NCR is a more reliable indicator of a poor prognosis for patients with CC. Patients with low NCR levels experienced a significantly shorter Overall Survival (OS) than patients with high levels. Multivariate analysis confirmed preoperative NCR levels as an independent predictor for overall survival with a hazard ratio of 3.3 (95% confidence interval 1.628–6.709, p < 0.001). Finally, we confirmed the predictive value of the NCR in an independent validation cohort and confirmed NCR as an independent prognostic factor for OS. Conclusion: Taken together, we discovered a new prognostic index (NCR) based on BMI, albumin, and CRP levels as an independent prognostic predictor of OS in patients with colon cancer. In all UICC stages, our newly developed NCR marker is able to distinguish patients with better and worse prognoses. We, therefore, propose that NCR may serve as a supplement to the TNM staging system to optimize the risk stratification in CC patients towards personalized oncology. In particular, NCR can be used in clinical trials to stratify patients with UICC II and III tumors and help better select patients who might benefit from adjuvant treatment.
An already existing shortage of nurses was exacerbated by the COVID-19 pandemic. Inactive (former) nurses were regarded as a so-called silent reserve and were called upon by various agencies to volunteer for nursing. The question arose as to what factors might encourage or hinder such volunteering and facilitate deployment.
First, inactive nurses were asked via an online survey whether they had registered for deployment or not and what the reasons were for this decision. Further information on professional background was collected, including the reason for having left the profession in the first place. Based on the results of the online survey, focus group discussions were conducted with registered and unregistered inactive nurses, with nurses who had returned to the profession permanently, and with care home managers.
Only one third of the participants in the online survey said they had registered for a temporary assignment during the pandemic. The main reasons for registering were that inactive nurses ‘wanted to do their bit’ to manage the crisis, felt it was their duty and/or felt a sense of belonging to the nursing profession. The main reasons given for not having registered was that respondents ‘could not see a reason at the moment’, had health concerns, and ‘other relevant job commitments’. The majority of respondents still had jobs related to health, care or nursing.
The topics covered in the focus group discussions included the following: perception of the pandemic as a crisis, identity as a nurse and sense of professional commitment, role of current occupation in the decision to register, winning over inactive nurses with a very negative attitude towards returning to care during a crisis situation, support measures and offers regarding a deployment in nursing.
Both in the online survey and in the focus group discussions, a sense of belonging to the nursing profession was evident among many participants. However, this identity does not necessarily lead to a willingness to return to nursing during a crisis situation. Weighing up the risk of deployment against the positive or negative experiences gained during the active period can influence willingness. However, the possibility of taking a break from current work and returning to nursing at short notice is not always given. Many inactive nurses continue to work in the health sector and fulfil equally important tasks during a crisis situation which render them unavailable for deployment.
Different kinds of support for those willing to return to nursing during a crisis situation and communication on conditions of deployments need to be implemented and continuously improved to offer the inactive nurses the greatest possible security and to enable a largely unbureaucratic deployment.
Materials and Methods:
Literature search was conducted using electronic MEDLINE/ Cochrane databases, relevant references, citations and hand search was conducted. Academic Colleges were contacted to identify relevant studies and full texts. Inclusion Criteria were Randomized clinical trials, human cohort and case series reporting increasing vertical dimension and restoring worn dentition in adults suffering from tooth wear using fixed, minimal invasive and adhesive techniques.
The search period spanned from 2000 up to January 2023. Of the 550 articles identified, 111 went throw full text screening for eligibility and 12 studies were included in our study.
Failure, follow-up period for all the studies were assessed. Attrition , Bruxism, increase of vertical dimension rates and mean time of failure were calculated using random effect models.
Results:
Tooth wear was reported equally in anterior and posterior region, and restorations were done in direct and indirect manners, mostly with pre-evaluation of the needed increase of vertical dimension. The mean of increased vertical dimension was 2.3 mm. The mean observation time of the restorations was 41.3 months with a minimum observation period of 12 months and a maximum of 84 months. Failure rate of all the included studies was 9.9% (95% CI: 91.00 % to 95.80%) high heterogeneity was detected in Failure rate with I2 of (93.85). Time to fail was calculated to be 37.5 months for 2458 cases (95% CI:32.32 to 91.13%). A fixed effect model was performed to calculate the event of increasing vertical dimension , the event rate was 81.72% (95% CI: 0.00 to 88.10%).
Conclusion:
The performance of direct and indirect restorations is satisfactory, and the failure rate is low, which leads us to conclude that these non-invasive restorations are a reliable and cost-effective middle-term treatment method to restore vertical dimension in moderate to severe worn dentition.
Conflict of interest: None
Pentathiepine sind siebengliedrige, heterocyclische Polysulfane. Sie gehören damit zur Gruppe organischer Polysulfide und somit zu einer Stoffklasse, die in den letzten Jahren wachsendes Interesse hinsichtlich pharmazeutisch/medizinisch nutzbarer Eigenschaften geweckt hat. Sie besitzen unterschiedliche biologische Wirkungen, die möglicherweise auf die Aktivierung durch Thiole, wie zum Beispiel Glutathion (GSH), zurückzuführen sind. Dazu gehören die Erzeugung von reaktiven Sauerstoffspezies und die oxidative Fragmentierung von DNA.
Pentathiepine zeigen sich als gelbe, schwer lösliche Feststoffe und sind in sauren Lösungen sehr stabil. In Lösungen, die Basen oder Nukleophile enthielten, nahm der Gehalt an Pentathiepinen jedoch sehr schnell ab. In dieser Arbeit sollte hauptsächlich untersucht werden, inwieweit sich die Stabilität der Pentathiepine auf die biologischen Eigenschaften auswirkt. Neben der Ermittlung der Verteilungskoeffizienten 23 verschiedener Pentathiepine, wurden auch enzymbasierte Assays durchgeführt.
Dazu gehörte die Bestimmung der Reversibilität der Hemmung an boviner Glutathionperoxidase-1 (GPx-1) sowie der Einfluss unterschiedlicher Inkubationsbedingungen auf die inhibitorische Wirkung. Dabei wurde für das untersuchte Pentathiepin mittels jump dilution keine irreversible Hemmung an boviner GPx-1 gefunden. Eine irreversible Inhibierung konnte jedoch für Mercaptobernsteinsäure gezeigt werden. Die Ergebnisse der unterschiedlichen Inkubationsbedingungen erlauben die Schlussfolgerung, dass der intakte Pentathiepinring wahrscheinlich nicht an der Hemmung der GPx-1 beteiligt ist, sondern die aus der Reaktion mit GSH gebildeten Abbauprodukte. Es konnte jedoch auch gezeigt werden, dass der Pentathiepinring mindestens als „Schwefeltransporter“ benötigt wird. Ein Übertrag des GPx-Assays auf die HPLC konnte als prinzipiell möglich, für die Pentathiepine jedoch als nicht geeignet gezeigt werden.
Im zweiten Teil der Arbeit wurden sechs Pentathiepine mit vier unterschiedlichen Grundgerüsten hinsichtlich ihrer Stabilität in Gegenwart von GSH untersucht. Dabei gab es hinsichtlich der Reaktivität der Pentathiepine sehr starke Unterschiede. Trotz dieser großen Unterschiede konnten keine Unterschiede hinsichtlich der GPx-Hemmung und der antiproliferativen Eigenschaften beobachtet werden. Auch eine Absenkung der intrazellulären GSH-Konzentration durch Inkubation mit DL-Buthioninsulfoximin in drei humanen Krebszelllinien mit unterschiedlichem Glutathiongehalt ergab keine Unterschiede zwischen den getesteten Substanzen. Sie waren nach Vorinkubation der Zellen durchgehend aktiver.
Aufgrund der vergleichsweise hohen Reaktivität in Gegenwart von GSH sollte ein Pentathiepin in einem proof of concept in Liposomen formuliert werden. Diese Formulierung sollte einerseits das Pentathiepin vor Reaktionen mit Thiolen wie GSH schützen, andererseits die Wasserlöslichkeit erhöhen. Dabei ergab sich, dass die Wasserlöslichkeit der Pentathiepine durch Formulierung in DOPC-Liposomen von unter 3 μM auf über 400 μM erhöht werden konnte. In Hinsicht auf die Stabilität ergab sich eine erhöhte Stabilität des untersuchten Pentathiepins in Anwesenheit von 10 mM GSH um den Faktor 4 in der Zeit bis zum vollständigen Abbau. Hinsichtlich der antiproliferativen Eigenschaften ergab sich keine Abnahme der Wirkung des Pentathiepins durch Formulierung in Liposomen.
Background
Neuroinflammation and maladaptive neuroplasticity play pivotal roles in migraine (MIG), trigeminal autonomic cephalalgias (TAC), and complex regional pain syndrome (CRPS). Notably, CRPS shares connections with calcitonin gene-related peptide (CGRP) in its pathophysiology. This study aims to assess if the documented links between CRPS and MIG/TAC in literature align with clinical phenotypes and disease progressions. This assessment may bolster the hypothesis of shared pathophysiological mechanisms.
Methods
Patients with CRPS (n = 184) and an age-/gender-matched control group with trauma but without CRPS (n = 148) participated in this case–control study. Participant answered well-established questionnaires for the definition of CRPS symptoms, any headache complaints, headache entity, and clinical management.
Results
Patients with CRPS were significantly more likely to suffer from migraine (OR: 3.23, 95% CI 1.82–5.85), TAC (OR: 8.07, 95% CI 1.33–154.79), or non-classified headaches (OR: 3.68, 95% CI 1.88–7.49) compared to the control group. Patients with MIG/TAC developed CRPS earlier in life (37.2 ± 11.1 vs 46.8 ± 13.5 years), had more often a central CRPS phenotype (60.6% vs. 37.0% overall) and were three times more likely to report allodynia compared to CRPS patients with other types of headaches. Additionally, these patients experienced higher pain levels and more severe CRPS, which intensified with an increasing number of headache days. Patients receiving monoclonal antibody treatment targeting the CGRP pathway for headaches reported positive effects on CRPS symptoms.
Conclusion
This study identified clinically relevant associations of MIG/TAC and CRPS not explained by chance. Further longitudinal investigations exploring potentially mutual pathomechanisms may improve the clinical management of both CRPS and primary headache disorders.
Trial registration
German Clinical Trials Register (DRKS00022961).
Einleitung/Hintergrund
DC_TRAIN_APHASIA ist eine multizentrische, randomisiert-kontrollierte Studie, die seit November 2019 unter Federführung der Universitätsmedizin Greifswald durchgeführt wird (ClinicalTrials.gov Identifier: NCT03930121). Die Studie untersucht, ob adjuvante transkranielle Gleichstromstimulation („transcranial direct current stimulation“, tDCS) den Erfolg einer 3‑wöchigen intensiven Sprachtherapie bei chronischer Aphasie steigern kann.
Material und Methode
Bis Ende 2024 sollen bundesweit 130 Patient:innen eingeschlossen werden. Die Entwicklung innovativer Rekrutierungsstrategien stellt seit Beginn der Studie eine Herausforderung dar. Neben gängigen Rekrutierungsmethoden wie der direkten Ansprache von Menschen mit Aphasie in Kliniken, Logopädiepraxen, Rehabilitationseinrichtungen und Selbsthilfegruppen wurden Radiowerbespots, Fernsehbeiträge und Auftritte in sozialen Medien erprobt.
Zwischenergebnisse
Bis zum aktuellen Zeitpunkt konnten 110 Patient:innen in die Studie eingeschlossen werden. Zum größten kurzzeitigen Rücklauf führte die Rekrutierung über einen Fernseh- bzw. Radiobeitrag. Den größten langfristigen Rücklauf ergab die Rekrutierung über Logopädie- und Neurologiepraxen, Selbsthilfegruppen und soziale Medien. Teilnehmer:innen berichteten als „Testimonials“ positiv von der Sprachtherapie und der Anwendung von tDCS, die sich als gut verträglich erwies.
Diskussion
Die multizentrische Studie DC_TRAIN_APHASIA prüft die Wirksamkeit von tDCS als adjuvante Applikation für intensive Sprachtherapie bei chronischer Aphasie. Die vorliegende Übersicht soll künftigen Studien als Leitfaden zur Rekrutierung von Stichproben dienen, die Menschen mit eingeschränkten kommunikativen Fähigkeiten umfassen.
Perception of climate change-related forest dieback in mountain forests among the local population
(2023)
Mountain forests provide multiple benefits but are threatened by climate change-induced forest dieback. Although many studies summarize perceptions of forest ecosystem services, relatively few deal with mountain forests. The local population’s perception of forest dieback in mountain forests in relation to climate change has rarely been investigated so far. Their perspective is relevant as local people are often deeply attached to “their” forests, they actively use forest ecosystems and—as voters and taxpayers—they need to support the state’s adaptation and funding measures. Therefore, this study investigates the climate change and forest dieback perception of local inhabitants in two mountain areas of Southern Germany (the German Alps and the Bavarian Forest) with a quantitative survey based on representative online samples (n = 709). Relying conceptually on van der Linden’s (J Environ Psychol 41:112–124, 2015. https://doi.org/10.1016/j.jenvp.2014.11.012) climate change risk perception model, the results show that experiential processing, cognitive and socio-cultural factors are related to locals’ forest dieback and climate change perception, while socio-demographics show no or few connections. Nearly two-thirds (64.7%) of the respondents perceive moderate to strong forest dieback, while more than half (55.0%) of the respondents already observe consequences of climate change. The perceptions of climate change and forest dieback are positively correlated with medium to high strength. This shows that forest dieback could be interpreted as an indicator of climate change, which is difficult to observe due to its long-term nature. We identify three groups of respondents regarding preferred forest adaptation strategies to climate change. In general, respondents support nature-based forest adaptation strategies over intense measures.
Toarciconiopteryx dipterosimilis gen. et sp. nov. is described from the Lower Toarcian of Grimmen (Western Pomerania, Germany) based on a hind wing. This enigmatic wing superficially resembles a dipteran forewing, but analysis in detail establishes that it belongs to the Neuroptera. We assign it to the Coniopterygidae with great confidence by its great concordance with the hind wings of that family, but a small possibility remains that it might belong to the Dipteromantispidae, although the very derived haltere-like hind wings of all its known members are entirely unlike it. We, therefore, consider it to be the oldest record of Coniopterygidae. We create the new subfamily Toarciconiopteryginae subfam. nov. for it, which is distinguished from other Coniopterygidae by its hind wings possessing two branches of RP and a proximal forking of M. These conditions are also known in some Sialidae (Megaloptera), supporting the hypothesis that Coniopterygidae is the sister group of all other Neuroptera, as Megaloptera is considered by most authors to be sister to Neuroptera. New interpretations of some aspects of the Coniopterygidae venation are proposed.
This anthology is about the representations and uses of medieval saints, heroes, and heroic events as elements of popular, local, and national culture during the 19th and 20th centuries in the Baltic Sea region: Scandinavia, Finland, Baltic countries, Northern Germany and North-Western Russia. Authors examine the processes of how medieval saints and heroes have been remembered, commemorated, interpreted, used, and reflected during modernity, and by whom. The focus of the anthology is on "doing" memory as a practice that commemorated the past and shaped spaces and identities in the present. It approaches the memory of saints and heroes, for example, Swedish Saints Birgitta and Eric, Danish Saint Knud, Kyivan Princess Olga, Swedish military leader in Finland Tyrgils Knutsson, Liv/Latvian warrior Imanta and Holsatian count Gerhard III as a shared heritage and as part of national, local and popular culture. The anthology contributes to the understanding of the Baltic Sea region through the study of saints, cults and heroic representations in the longue durée between the Middle Ages and modernity. It also adds nuance to the use of popular concepts of memory studies, particularly an update of Pierre Nora’s lieux de mémoire.
Clear cell renal cell carcinoma is the most frequent malignant kidney tumor in adults. It is often associated with biallelic VHL mutations. We characterized our cell lines according to their HIF expression pattern. Cell lines RCC4, UOK-220 and CaKi-2 were assigned to subtype H1H2, cell lines 786-O and A-498 were assigned to subtype H2 and cell lines CaKi-1 and Rc-124 were assigned to subtype VHLwt.
Previous work of our group had shown, that p53 can be activated in ccRCC following irradiation but is not able to induce apoptosis. An important link to p53 activity with strong antiapoptotic qualities is the NFB pathway, which can be activated e. g. by irradiation.
We irradiated the three subtypes previously established as well as two control cell lines, SAOS-2 (p53 negative cell line) and HEK 293 (contains functioning p53) with 2 Gy and 10 Gy and analyzed several proteins of the pathway by using western blots. Several target genes with antiapoptotic qualities were analyzed by using rt-PCR.
We found, that out of the cell lines analyzed, both control cell lines (SAOS-2, HEK 293) showed the strongest response (activation of the NFB pathway) following irradiation. Among the three ccRCC subtypes the VHLwt cell lines showed the strongest response. H2 cell lines showed almost no response at all.
A connection between the missing ability of p53 to induce apoptosis and an induction of transcription factors by the NFB pathway could not be determined. We also could not determine biological differences between the subtypes.
We analyzed, whether any NFB proteins were present in the nucleus following irradiation and found, that only p50 homodimers were present in the nucleus. This might point towards p50 homodimers, which have been described to have different characteristics than heterodimers. More research is needed to analyze this important finding.
Seventeen bacterial strains able to suppress plant pathogens have been isolated from healthy Vietnamese crop plants and taxonomically assigned as members of the Bacillus cereus group. In order to prove their potential as biocontrol agents, we perform a comprehensive analysis that included the whole-genome sequencing of selected strains and the mining for genes and gene clusters involved in the synthesis of endo- and exotoxins and secondary metabolites, such as antimicrobial peptides (AMPs). Kurstakin, thumolycin, and other AMPs were detected and characterized by different mass spectrometric methods, such as MALDI-TOF-MS and LIFT-MALDI-TOF/TOF fragment analysis. Based on their whole-genome sequences, the plant-associated isolates were assigned to the following species and subspecies: B. cereus subsp. cereus (6), B. cereus subsp. bombysepticus (5), Bacillus tropicus (2), and Bacillus pacificus. These three isolates represent novel genomospecies. Genes encoding entomopathogenic crystal and vegetative proteins were detected in B. cereus subsp. bombysepticus TK1. The in vitro assays revealed that many plant-associated isolates enhanced plant growth and suppressed plant pathogens. Our findings indicate that the plant-associated representatives of the B. cereus group are a rich source of putative antimicrobial compounds with potential in sustainable agriculture. However, the presence of virulence genes might restrict their application as biologicals in agriculture.
Peatlands contribute to a wide range of ecosystem services. They play an important role as carbon sinks in their natural state, but when they are drained, they cause carbon emissions. Rewetting drained peatlands is required to reduce carbon emissions and create new carbon sinks. However, drained peatlands are commonly used as grassland or croplands; therefore, alternative agriculture schemes are required following rewetting. Paludiculture, i.e., agriculture on wet and rewetted peatlands, is an option in these areas after rewetting to produce biomass sustainably. Monitoring of peatland management is challenging, yet needed to ensure a successful rewetting and plantation of, e.g., Phragmites australis and Typha spp., two plants which are commonly used in paludiculture. Remote sensing is an excellent tool for monitoring the vegetation composition of vast rewetted peatland regions. However, because many peatland species have similar spectral characteristics, such monitoring is ideally based on high-spatial, high-temporal hyperspectral images. Data that complies with all these requirements does not exist on a regular basis. Therefore, we assessed the potential for mapping peatland vegetation communities in the Peene and Trebel river basins of the federal state of Mecklenburg-Western Pomerania, Germany, using multi-date hyperspectral (PRISMA) data. We used regression-based unmixing to map fractions of different peatland vegetation classes. Results were analyzed with regard to the contribution of multi-date observations and, in comparison, to multispectral datasets (Landsat-8/Sentinel-2). Our results showed that different classes are best mapped at different observation dates. The multi-date hyperspectral datasets produced less Mean Absolute Error (MAE = 16.4%) than the single-date hyperspectral images (ΔMAE + 1%), with high accuracies for all classes of interest. Compared to the results obtained with multispectral data from similar acquisition dates and annual spectral-temporal metrics (STM), the results from hyperspectral data were always clearly superior (ΔMAE + 4%). Besides the superior performance during comparisons, our results also indicate that information that can be derived from the hyperspectral data with the regression-based unmixing goes clearly beyond that of discrete classification. With more hyperspectral sensors coming up and an expected higher availability of multi-data hyperspectral imagery, these data can be expected to play a bigger role in the future monitoring of peatlands.
The male genitalia of pholcid spiders, which is one of the most species-rich spider families, are characterized by a procursus, which is a morphologically diverse projection of the copulatory organ. It has been shown that the procursus interacts with the female genitalia during copulation. Here, we investigate the function of the procursus in Gertschiola neuquena, a species belonging to the early branched and understudied subfamily Ninetinae, using behavioural and morphological data. Although many aspects of the copulatory behaviour of G. neuquena follow the general pattern described for the family, males use only one pedipalp during each copulation. Based on our micro-CT analysis of cryofixed mating pairs using virgin females, we can show that the long and filiform procursus is inserted deeply into the unpaired convoluted female spermatheca, and the intromittent sclerite, the embolus, is rather short and stout only reaching the most distal part of the female sperm storage organ. Histological data revealed that sperm are present in the most proximal part of the spermatheca, suggesting that the procursus is used to allocate sperm deeply into the female sperm storage organ. This represents the first case of a replacement of the sperm allocation function of the intromittent sclerite in spiders.
Background
The alignment of large numbers of protein sequences is a challenging task and its importance grows rapidly along with the size of biological datasets. State-of-the-art algorithms have a tendency to produce less accurate alignments with an increasing number of sequences. This is a fundamental problem since many downstream tasks rely on accurate alignments.
Results
We present learnMSA, a novel statistical learning approach of profile hidden Markov models (pHMMs) based on batch gradient descent. Fundamentally different from popular aligners, we fit a custom recurrent neural network architecture for (p)HMMs to potentially millions of sequences with respect to a maximum a posteriori objective and decode an alignment. We rely on automatic differentiation of the log-likelihood, and thus, our approach is different from existing HMM training algorithms like Baum–Welch. Our method does not involve progressive, regressive, or divide-and-conquer heuristics. We use uniform batch sampling to adapt to large datasets in linear time without the requirement of a tree. When tested on ultra-large protein families with up to 3.5 million sequences, learnMSA is both more accurate and faster than state-of-the-art tools. On the established benchmarks HomFam and BaliFam with smaller sequence sets, it matches state-of-the-art performance. All experiments were done on a standard workstation with a GPU.
Conclusions
Our results show that learnMSA does not share the counterintuitive drawback of many popular heuristic aligners, which can substantially lose accuracy when many additional homologs are input. LearnMSA is a future-proof framework for large alignments with many opportunities for further improvements.
Fortbildungen sind zentrale Lerngelegenheiten für die Professionalisierung pädagogischen Personals in Kindertageseinrichtungen. Inwiefern Inhalte von Fortbildungen in der alltäglichen Praxis Anwendung finden, stellt ein zentrales Qualitätskriterium von Fortbildungen dar. Daher existieren vielfältige Vorstellungen und Konzepte darüber, wie diese Anwendung – der Transfer – unterstützt werden kann. Der vorliegende Beitrag greift theoretische und empirische Erkenntnisse aus der Bildungs- und Lehr-Lernforschung auf und stellt ein Modell der Wissenstransformation von der Theorie in Handlungen und von Handlungen in die Theorie vor. Zentral an diesem Modell ist die Vorstellung, dass Wissen durch verschiedene Akteure (Fortbildner_innen sowie pädagogische Fachkräfte) transformiert wird und kontextuelle sowie individuelle Merkmale diesen Transformationsprozess beeinflussen. Implikationen für Forschung und -praxis werden diskutiert.
The multi-cell Penning–Malmberg trap concept has been proposed as a way to accumulate and confine unprecedented numbers of antiparticles, an attractive but challenging goal. We report on the commissioning and first results (using electron plasmas) of the World's second prototype of such a trap, which builds and improves on the findings of its predecessor. Reliable alignment of both ‘master’ and ‘storage’ cells with the axial magnetic field has enabled confinement of plasmas, without use of the ‘rotating wall’ (RW) compression technique, for over an hour in the master cell and tens of seconds in the storage cells. In the master cell, attachment to background neutrals is found to be the main source of charge loss, with an overall charge-confinement time of 8.6 h. Transfer to on-axis and off-axis storage cells has been demonstrated, with an off-axis transfer rate of 50% of the initial particles, and confinement times in the storage cells in the tens of seconds (again, without RW compression). This, in turn, has enabled the first simultaneous plasma confinement in two off-axis cells, a milestone for the multi-cell trap concept.
Das Zurücktreten der Erzählstimme in der Literatur der Hebräischen Bibel wurde oft benannt. Dies wurde allerdings nur selten mit der erzähltheoretischen Analysekategorie des Modus fundiert. Letzteres gilt besonders für die Darstellung von Figurenrede. Dabei ist umstritten, ob sich neben direkter und indirekter Rede auch erlebte Rede in der Hebräischen Bibel nachweisen lässt. Diese vor allem von Meir Sternberg vertretene Möglichkeit hat Cynthia L. Miller abgelehnt. Millers Einwände lassen sich aber mit einer linguistisch fundierten Erzählanalyse hinterfragen, was die grundsätzliche Möglichkeit erlebter Rede bei wᵉhinne-Phrasen begründet.
The controlled formation and adjustment of size and density of magnetic skyrmions in Ta/CoFeB/MgO trilayers with low Dzyaloshinskii–Moriya interaction is demonstrated. Close to the out-of-plane to in-plane magnetic spin reorientation transition, we find that small energy contributions enable skyrmion formation in a narrow window of 20 pm in CoFeB thickness. Zero-field stable skyrmions are established with proper magnetic field initialization within a 10 pm CoFeB thickness range. Using magneto-optical imaging with quantitative image processing, variations in skyrmion distribution and diameter are analyzed quantitatively, the latter for sizes well below the optical resolution limit. We demonstrate the controlled merging of individual skyrmions. The overall demonstrated degree of comprehension of skyrmion control aids to the development of envisioned skyrmion based magnetic memory devices.
Recent experimental campaigns in the Wendelstein 7-X stellarator, a
plasma-confining device designed to investigate the Magnetic Confinement Fusion
(MCF) approach to generating electrical power, have shown that the injection of
fuelling pellets had an unexpected and considerable impact on the performance of
the plasma. Rather than simply refuelling the device and `diluting' the plasma
energy, pellet injection is followed by a significant increase in the ratio of
the ion temperature to the electron temperature. It has been suggested that this
is not merely due to the improved confinement following the reduction of
turbulent transport after the pellet material has homogenised with the bulk
plasma, but also due to a direct transfer of energy from electrons to ions. The
proposed mechanism for this energy transfer is the ambipolar expansion of the
pellet plasmoid, the localised plasma structure produced by the
ionisation of ablated pellet material, along magnetic field lines.
Early work on pellet plasmoid expansion predicted that half the heating power
deposited in plasmoid electrons by collisions with hot ambient electrons is
transferred to plasmoid ions in the form of flow velocity as the plasmoid
expands. The complicated nature of the system of the pellet plasmoid embedded in
the ambient plasma, particularly the behaviour of electrons, which experience
many collisional and collisionless phenomena on multiple disparate timescales,
means that early models of the expansion were not wholly self-consistent, but
rather made use of strong approximations that apply in some regions of the
plasmoid but not in others. For example, only electrons and ions associated with
the plasmoid were rigorously treated, meaning that the framework was one of
`expansion into vacuum'. Combined with the assumption of Maxwellian electrons,
this led to an electric potential that was unbounded at infinity. Naturally, the
validity of the conclusions of such a model are called into question because the
approximations lose their validity far from the plasmoid and as time advances,
yet predictions about the final state of the plasma are desired. A deeper
investigation is required: careful consideration of the phenomena in question
and the timescales (and lengthscales) on which they act must be made in order to
rigorously construct a model that is valid throughout the entire expansion.
The first two papers presented in this thesis iterate on the model established
in the paper that first predicted the electron-to-ion energy transfer; their aim
was to find out how the character of the expansion changes with a more
sophisticated and accurate description of various phenomena, while remaining
within the existing framework of expansion into vacuum. Ultimately, we find that
the qualitative character is unchanged, and that approximately half the heating
power deposited in plasmoid electrons is transferred to ions.
Two other papers in this thesis address the limitations of the original model.
This is achieved by properly considering the electron kinetic problem in a
plasmoid. One paper considers the electron kinetic problem when electrons are
highly isotropised. In this case the kinetic equation can be integrated to
remove all but two independent variables, which is the maximum possible
reduction considering it is a time-dependent problem. The full nonlinear
integro-differential Landau self-collision operator is integrated exactly and
few approximations are made, leading to a rather general kinetic equation.
However, for fuelling pellets some anisotropy in the electron distribution is
expected. Another paper considers the electron kinetic problem (and the entire
plasmoid expansion) allowing for electron anisotropy. Careful consideration of
the ordering of timescales of electron phenomena in a pellet plasmoid leads to a
steady-state kinetic problem that we call collisional quasi-equilibrium (QE). QE
appears in many ways similar to the collisional steady-state characterising a
true thermal equilibrium. It was found that the time-dependent kinetic problem
of the earlier paper, with isotropic electrons, produces the QE distribution
function, corroborating the existence of the QE state. We then take moments of
the electron kinetic equation that is valid on the expansion timescale, assuming
that the electron distribution is that given as the solution to the QE kinetic
problem. This is completely analogous to what is done to obtain the Braginskii
equations or any Chapman-Enskog theory. The result is a set of equations for the
long-term evolution of the macroscopic quantities that describe the distribution
function existing in a quasi-steady-state at each point in time. It is from this
point that one may feasibly describe the plasmoid expansion with an accurate
picture of the electron kinetics and finally obtain the electron-to-ion energy
transfer so desired in a rigorous model of the expansion.
From a broader point of view, the two frameworks provided by these rigorous
investigations of the electron kinetic problem serve as a basis for the future
study of plasmoids. Such a `first-principles' approach to plasmoid dynamics is
novel and interesting in its own right, but it will be demonstrated that such an
approach is essential for pellet plasmoids owing to the fact that they are
poorly described by the `standard tools' of plasma physics.
Using the QE framework it was found that, once more, about half the heating
power experienced by plasmoid electrons is transferred to plasmoid ions. The
incredible robustness of the prediction of such an energy transfer is, in the
author's opinion, the result of the self-similar nature of the expansion found
as a solution to the original model. As a rule, the profiles of self-similar
solutions tend to be attractors for the `real', more complicated, system, and
the qualitative predictions involving no parameters, of which the
electron-to-ion energy transfer is one, tend to be very sturdy.
Aside from fuelling pellets, composed of hydrogen or deuterium, one paper in
this thesis investigates the physics of high-Z pellets that are designed to
terminate the plasma safely in the event of a `disruption', where much of the
magnetic field energy is channelled into a runaway electron beam with
potentially disastrous consequences if the beam encounters a plasma-facing
component. The paper draws on the work carried out in the paper concerning the
kinetic problem of isotropised electrons in a plasmoid.
This thesis is `cumulative'; the vast majority of the work carried out is
described within a set of Papers, labelled A-E, placed at the back of the text.
There is a preceding `wrapper text' (given in numbered Sections) tasked with
introducing the reader to the topic, guiding the reader through the papers, and
expounding some of their main results. Some amount of material not present in
the papers is also provided in the wrapper text. Naturally, the wrapper text
mainly focusses on the results of the papers which are under my first
authorship. In the course of publishing papers over an extended period of time
the nomenclature is bound to vary. Although it is mostly consistent between the
papers, a few difference do arise, and the section `Common symbols and
subscripts' is provided in the frontmatter to alleviate confusion. Particular
care should be taken with the symbols x and z; both can refer to the
coordinate parallel to the magnetic field line, but in papers where z is used
for this purpose x tends to have another definition. In the wrapper text the
choice of symbols is generally chosen to reflect those in the corresponding
paper.
Minced Cartilage Implantation in Acetabular Cartilage Defects: Case Series with 2-Year Results
(2023)
Objective
The objective was to evaluate clinical outcome and safety of arthroscopic, autologous minced cartilage implantation for acetabular cartilage lesions observed during hip arthroscopy to treat femoroacetabular impingement syndrome (FAIS).
Design
Eleven male patients, average age: 29.4 ± 5.4 years, average body mass index (BMI): 24.2 ± 2.2 kg/m2, scheduled for hip arthroscopy due to FAIS accompanied by an acetabular cartilage lesion were included in the case series. Cartilage tissue was harvested and minced from the loose cartilage flap at the chondrolabral lesion by arthroscopic shaver, augmented with autologous conditioned plasma, implanted into the defect, and fixated by autologous thrombin. Concomitant interventions were performed as indicated. The patients were evaluated preoperatively and at 24-month follow-up, using the International Hip Outcome Tool-12 (iHOT-12) and Visual Analog Scale (VAS) pain score and by magnetic resonance imaging (MRI) using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) grading scale at the 2-year follow-up.
Results
The defect size was on average 3.5 cm2 (1.5-4.5 cm2). From preoperatively to 2 years postoperatively, the iHOT-12 significantly improved from 50.2 ± 18 to 86.5 ± 19 (P < 0.0001), and pain score decreased from 5.6 ± 1.8 to 1.0 ± 1.5 (P < 0.0001) on the Visual Analog Scale pain score. Regarding functional outcome and pain, 10 of the 11 patients and all patients reached the minimal clinically important difference (MCID), respectively. The postoperative average MOCART score was 87.2 (± 9.2). No adverse events or reoperations were observed.
Conclusions
Arthroscopic, autologous minced cartilage implantation for treating full-thickness acetabular cartilage lesions in FAIS shows statistically and clinically significant improvement at short-term follow-up.
Background:
Minced cartilage implantation (MCI) has seen a renaissance in recent years. In this evolved technique, human articular cartilage is harvested with an arthroscopic shaver, augmented with platelet-rich plasma (PRP), and implanted with autologous thrombin. This modified technique combines the possibility of cell-based surgical cartilage repair with a minimally invasive autologous 1-step procedure. However, evidence on cell survival and preserved function after shaver-based mincing and PRP supplementation is limited.
Purpose:
To evaluate the effects of arthroscopic shaver mincing and augmentation with PRP on human cartilage tissue.
Study Design:
Controlled laboratory study.
Methods:
Standardized samples were taken from 12 donors during autologous MCI. A comparison of cell outgrowth, cell viability, proliferation capacity, and ability to produce extracellular matrix–specific proteoglycans after chondrogenic redifferentiation was made between cartilage taken by curettage from the border of the cartilage defect, cartilage tissue minced by an arthroscopic shaver, and cartilage tissue minced by an arthroscopic shaver that was additionally augmented with autologous PRP.
Results:
There was no difference between all 3 groups in terms of cell outgrowth or proliferation capacity. Metabolic activity relative to the cell number of chondrocytes isolated from shaver-minced cartilage was higher compared with chondrocytes isolated from cartilage that was derived by curettage or shaver-minced cartilage that was augmented with PRP. After chondrogenic stimulation, the normalized proteoglycan content was higher in spheroids of cells derived from shaver-minced cartilage augmented with PRP than in spheroids of cells derived from curettage. A high correlation of cell outgrowth, proliferation capacity, and viability between isolated cells from all 3 groups taken from an individual donor was observed.
Conclusion:
Chondrocytes isolated from human cartilage tissue that was harvested and minced with an arthroscopic shaver remained viable and proliferative. The augmentation of shaver-minced cartilage with PRP led to the enhanced proteoglycan production of chondrogenic spheroids in vitro, pointing toward the development of a cartilage-specific extracellular matrix. This in vitro study yields promising results regarding the use of an arthroscopic shaver and augmentation with PRP in the context of MCI.
Clinical Relevance:
Knowledge that shaver mincing and augmentation with PRP are feasible for processing articular cartilage during MCI is highly relevant for surgical cartilage repair.
Introduction: Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, noncoding ribonucleic acids that are involved in the posttranscriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in the serum and vitreous of human patients with and without vessel-associated retinal diseases. Methods: Relative quantification by quantitative real-time polymerase chain reaction was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinal vein occlusion compared with control patients. Results: In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in receiver operating characteristic (ROC) and area under the ROC curve analysis. Conclusion: The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis.
In future fusion reactors disruptions must be avoided at all costs. Disruptions due to the density limit (DL) are typically described by the power-independent Greenwald scaling. Recently, a power dependence of the disruptive DL was predicted by several authors (Zanca et al 2019 Nucl. Fusion 59 126011; Giacomin et al 2022 Phys. Rev. Lett. 128 185003; Singh and Diamond 2022 Plasma Phys. Control. Fusion 64 084004; Stroth et al 2022 Nucl. Fusion 62 076008; Brown and Goldston 2021 Nucl. Mater. Energy 27 101002). It is investigated whether this increases the operational range of the tokamak. Increasing the heating power in the L-mode can induce an L-H transition, and therefore a power-dependent DL and the L-H transition cannot be considered independently. The different models are tested on a data base for separatrix parameters at the separatrix of ASDEX Upgrade and compared with the concept (SepOS) presented in Eich and Manz (2021 Nucl. Fusion 61 086017). The disruptive separatrix density scales with the power ne ∝ P0.38±0.08 in good agreement to all models. Also the back transition from high to low (H-L) confinement shows an approximately Greenwald scaling with an additional power dependence ne ∝ P0.4 according to the SepOS concept. For future devices operating at much higher heating power such a power scaling may allow operation at much higher separatrix densities than are common in H-mode operation. Preconditions to extrapolation for future devices are discussed.
The pulse length dependence of a reactive high power impulse magnetron sputtering (HiPIMS) discharge with a tungsten cathode in an argon+oxygen gas mixture gas was investigated. The HiPIMS discharge is operated with a variable pulse length of 20–500 µs. Discharge current measurements, optical emission spectroscopy of neutral Ar, O, and W lines, and energy-resolved ion mass spectrometry are employed. A pronounced dependence of the discharge current on pulse length is noted while the initial discharge voltage is maintained constant. Energy-resolved mass spectrometry shows that the oxygen-to-tungsten (O+/W+) and the tungsten oxide-to-tungsten (WO+/W+) ion ratio decreases with pulse length due to target cleaning. Simulation results employing the SDTrimSP program show the formation of a non-stoichiometric sub-surface compound layer of oxygen which depends on the impinging ion composition and thus on the pulse length.
Semiosis is the process in which a sign unfolds its effect—the meaning that humans ‘suddenly’ see in acts, objects or facts. The semiotic tenet is applied to the event and the question of why we narrate it. The graphics are dedicated to the author’s contribution: ‘The event and its consequences: a semiotic analysis.’